Exploring the boundaries of direct detection and characterization of labile isomers – a case study of copper(II)–dipeptide systems

Eszter Tóth, Nóra V. May, Antal Rockenbauer, Gábor Peintler and Béla Gyurcsik Dalton Trans., 2017,46, 8157-8166 ABSTRACT The investigation of the linkage isomers of biologically essential and kinetically labile metal complexes in aqueous solutions poses a challenge, as these microspecies cannot be separately studied. Therefore, derivatives are commonly used to initially determine the stability or spectral characteristics of at least one of the isomers. Here we directly detect the isomers, describe the metal ion coordination sphere, speciation and thermodynamic parameters by Read More …

A novel 1,3,5-triaminocyclohexane-based tripodal ligand forms a unique tetra(pyrazolate)-bridged tricopper(II) core: solution equilibrium, structure and catecholase activity

Attila Szorcsik, Ferenc Matyuska, Attila Bényei, Nóra V. Nagy, Róbert K. Szilágyi and Tamás Gajda* Dalton Trans., 2016, 45, 14998-15012   ABSTRACT Copper(II) complexes of a polydentate tripodal ligand L × 3HCl (L = N,N’,N’’-tris(5-pyrazolylmethyl)-cis, cis-1,3,5-triaminocyclohexane) were characterized in both solution and solid states. Combined evaluation of potentiometric, UV-VIS, and EPR data indicated the formation of two mononuclear (CuHL, CuL) and three trinuclear (Cu3H−xL2, x = 2, 3, 4) complexes. The high stability and spectroscopic properties of the CuL species indicate Read More …